Method of welding stiffenings of plates, particularly of shell plates and arrangement for applying said method

ABSTRACT

Method and apparatus for welding stiffening elements to a plate in which the plate is clamped to a tiltable support table, a stiffening element supported in holders is placed against the plate and clamped to it and to the table by plural clamps, the stiffening element is welded to the plate by welding it progressively from opposite sides, and releasing clamps sequentially as the welding progresses.

United States Patent 91 Domanski et a1.

[ METHOD OF WELDING STIFFENINGS OF PLATES, PARTICULARLY OF SHELL PLATESAND ARRANGEMENT FOR APPLYING SAIDMETHOD [76] Inventors: BonifacyDomanski, Fitelberga 5/5,

Gdansk-Wrzeszcz; Michal Kleminski, Grobla 1 8/ 1 1, Gdansk; ZdzislawZieba, Powstania Wielkopolskiego 68/12, Gdynia, all of Poland [22]Filed: June 17, 1970 [21] Appl. No.: 47,055

[52] US. Cl. 29/457, 29/200 P, 29/462, I

[51] Int. Cl. B23k 31/00 [58] Field of Search. 228/4, 44, 49; 29/200 P,29/200 .1, 428, 457, 462; 219/124, 125, 160

[56] References Cited UNITED STATES PATENTS Lindmark 113/131 [1113,795,968 1 Mar. 12, 1974 2,142,109 1/1939 Burke 113/112 3,291,36012/1966 Linnander 238/44 3,561,663 2/1971 Wenzlaff..... 228/25 2,866,88912/1958 Dempsey 219/160 Primary Examiner-J. Spencer Overholser AssistantExaminer-Robert J. Craig Attorney, Agent, or Firm-Irvin A. Lavine [5 7]ABSTRACT Method and apparatus for welding stiffening elements to a platein which the plate is clamped to a tiltable support table, a stiffeningelement supported in holders is-placed against the plate and clamped toit and to the table by plural clamps, the stiffening element is weldedto the plate by welding -it' progressively from opposite sides, 'andreleasing clamps sequentially as the welding progresses.

9 Claims, 2 Drawing Figures METHOD OF WELDING STIFFENINGS OF PLATES,PARTICULARLY OF SHELL PLATES AND ARRANGEMENT FOR APPLYING SAID METHODThe individual elements of a ships hull plates and deck, composed, insubstance, of plate panels, must be stiffened. Generally, as stiffeningelements there are used steel sections which are permanently fastenedeventually preliminarily or to cut out and eventually preliminarily orshaped plate panels. For that purpose, by means of transportationsystems now known, readymade plate panels were delivered to a weldingstand fitted with movable welding heads fastened on a supportingstructure specially designed for that purpose. In a correspondingposition plate panels were fastened on an immobile base provided withfastening elements. Another delivering system delivered ready-madestiffing elements onto a plate panel resting on a stationary base of thewelding stand. The stiffening element, placed on the plate panel wasthen clamped by means of a number of clamps installed above said elementon a foot-operated system specially designed for that purpose;afterwards, the weld joining the stiffening element with the plate-panelwas made.

A main drawback of said method of joining stiffening elements to platepanels, so far as elements of the hull plating and ships deck areconcerned, is that in order to carry out a double weld the plane of theplate panel and the flange or web of the steel section from which thestiffening element is manufactured must form a right angle. Otherwise,it is necessary to carry out during the welding operation one part ofthe weld, afterwards, the plate panel with the stiffening elementwelded-on on one side had to be turned, and after re-placing and fixingthe plate panel on the stationary base as well as after clamping thestiffening element to the plate panel and base, the other part of theweld had to be carried out on the other side of the stiffening element.Apart from that, another drawback of the known welding methods, so faras the ships elements are concerned, is that stiffening elements areclamped only in the direction perpendicular to the plane of the platepanel,.

Said drawbacks are eliminated by the method of welding stiffenings toplates, particularly to hull plates which is the subject of the presentinvention.

According to said invention method, the plate panels are made ready forwelding, and the stiffening elements are delivered on to the weldingstand by means of conveyors and stowed on a base shaped so that it formsa tilting table capable of being tilted by means of known hydraulic,pneumatic or electric mechanisms. The tilting table is fitted with anumber of fastening elements, e.g., magnets, for fastening the deliveredplate panel on its top. Then, by means of a co-acting conveyor,readymade stiffening elements are delivered on to the welding stand. Tosave space, it is advantageous that the stiffening elements be deliveredin a direction which is in line with the direction of the plate paneldelivery and that their positioning, oblique or perpendicular to thedirection of movement of the plate panels, should be effected on thewelding stand.

The ready-made stiffening element delivered according to said inventionmethod is caught by a number of corresponding movable holders shaped sothat irrespective of the cross section of the stiffening element theyensure a strong and temporarily correct catching of said elements.Movable holders are fastened on a supporting bridge structure movabletowards the tilting table above the plane of the plate panel. After anumber of holders have caught the stiffening element, it is lowered bythem until it engages the panel. Then, according to the invention methodboth the panel thus secured to the tilting base and the stiffeningelement supported on it and held by means of the holders areadditionally clamped to the top of the tilting table by means of clamps.It is advantagenous to fasten the clamps to the same bridge structure towhich the holders of the stiffening element are fastened. On completionof said operations the welding heads start working, simultaneouslycarrying out the weld from both sides of the stiffening element, andwhat is unique, irrespective of the size of the angle created by theplane of the panel with webs or with the base of the stiffening element.During the welding operation as the weld is carried out in turn, holdersof the stiffening element are released and after welding on the wholeelement its clamps and/or the clamps of the plate panel are released.

An advantage of the invention method is the possibility ofsimultaneously carrying out the weld from both sides of the stiffeningelement irrespective of the shape of the cross section of the stiffeningelement as well as irrespective of the size of the angle which existsbetween it and the plate. The size of that angle changes, depending onthe requirements, as the table tilts. Simultaneous welding from bothsides avoids the necessity for turning of the panel so that welding iseffected from only one support. Another advantage of the present methodis that the stiffening element is clamped to the plate panel during thewelding operation and simultaneously clamped by a number of holders,which prevent its being eventually shifted towards the panel under theinfluence of a component of an oblique force resulting from thedistribution of the clamping force into a force acting along the web ofthe stiffening element and into a forceacting along the inclined platepanel.

In the drawings:

FIG. 1 is an elevational view of an apparatus for welding in accordancewith the present invention method, taken on the line A-A of FIG. 2.

FIG. 2 is a plan view of the apparatus shown in F IG. 1.

Referring now to the drawings, wherein like or corresponding referencenumerals are used for like or corre sponding parts throughout theseveral views, there is shown in FIG. 1 a table 1 which is supported fortilting movement in bearings 12. Bearings 12 do not appear in FIG. 2,being concealed by bridge 9, to which reference will be hereinaftermade. For tilting the table 1, there is provided a tilting mechanism,generally designated 11; in its preferred form, the tilting mechanism 11 comprises known hydraulic, pneumatic or electric mechanisms which areplaced at the four corners of the table 1, and operable in known mannerto tilt table 1 while it is supported by the bearings 12.

Adjacent the central portion of the table there are a plurality ofmagnets 2, which are used as fastening elements for fastening platepanels to the table 1. The table 1 is also provided with rollers 3 tofacilitate the movement of plate panels on the table 1.

In association with the table 1 is a gantry 4, which includes a bridge 9extending over the table 1 at the central part thereof, as is shown inFIGS. 1 and 2. The bridge 9 carries a plurality of releasable holders 5,and a plurality of releasable clamps 6. The holders 5 are movable, andare shaped so that they are able to securely grasp and hold a number ofdifferent shapes of commonly used stiffening elements, which stiffeningelements may be bars, T-bars and L-bars. The clamps 6 are used to clampboth the plate and the stiffening element to the table 1.

Also carried by the bridge 9 of the gantry 4 are welding heads 7, whichare movable along the bridge 9, each welding head 7 being provided withtwo welding units so that welding action can be carried outsimultaneously from both sides, while the welding head 7 moves, therebyeffecting progressive welding from two sides. Preferably, as the weldingheads 7 move along the bridge 5, progressively effecting the weld fromboth sides simultaneously, the holders 5 and clamps 6 are seriallyreleased.

To support and facilitate the welding operation, the table 1 is providedwith conveyors 8 which function to move plate panels so that properportions of the panels are positioned beneath the bridge 9 of gantry 4for attachment of stiffening elements thereto by the above noted weldingoperations. In addition, a crane 10 is provided adjacent the table 1 inorder to enable movement of the plate panels to or from the table 1.

What we claim is 1. A method of welding stiffening elements at aninclined'angle to plates comprising:

releasably fastening a plate panel to a tiltable supporting table,

tilting said table and the plate panel releasably fastened thereto,

clamping a stiffening element against said plate panel in an inclinedposition relative to said plate panel,

and welding said stiffening element to said plate panel from both sidesof said element simultaneously and progressively along the joint betweensaid clamped elements and said panel.

2. The method of claim 1, wherein said stiffening element is held in aplurality of releasable holding elements, and said holding elements areserially released as said welding is effected.

3. The method of claim 1, said clamping being effected by a plurality ofreleasable clamping elements, and said clamping elements being seriallyreleased as said welding is effected.

4. Apparatus for supporting and welding plates and stiffening elementscomprising:

a table,

bearing means for supporting a portion of said table,

means for tilting said table on said bearing means,

supporting means extending over said table,

a plurality of means for releasably holding stiffening elements carriedby said supporting means,

plural welding means, and means for supporting said welding means onsaid supporting means for simultaneously welding on opposite sides of astiffening element carried by said holding means.

5. The apparatus of claim 4, said supporting means comprising a gantryhaving a bridge extending over said table.

6. The apparatus of claim 4, and further comprising clamping means onsaid supporting means for clamping a said stiffening element and plateagainst said table.

7. The apparatus of claim 4, and fastening means on said table forfastening a plate thereto.

8. The apparatus of claim 7, said fastening means comprising a pluralityof magnetic means.

9. The apparatus of claim 4, said table having conveyor means associatedtherewith.

1. A method of welding stiffening elements at an inclined angle toplates comprising: releasably fastening a plate panel to a tiltablesupporting table, tilting said table and the plate panel releasablyfastened thereto, clamping a stiffening element against said plate panelin an inclined position relative to said plate panel, and welding saidstiffening element to said plate panel from both sides of said elementsimultaneously and progressively along the joint between said clampedelements and said panel.
 2. The method of claim 1, wherein saidstiffening element is held in a plurality of releasable holdingelements, and said holding elements are serially released as saidwelding is effected.
 3. The method of claim 1, said clamping beingeffected by a plurality of releasable clamping elements, and saidclamping elements being serially released as said welding is effected.4. Apparatus for supporting and welding plates and stiffening elementscomprising: a table, bearing means for supporting a portion of saidtable, means for tilting said table on said bearing means, supportingmeans extending over said table, a plurality of means for releasablyholding stiffening elements carried by said supporting means, pluralwelding means, and means for supporting said welding means on saidsupporting means for simultaneously welding on opposite sides of astiffening element carried by said holding means.
 5. The apparatus ofclaim 4, said supporting means comprising a gantry having a bridgeextending over said table.
 6. The apparatus of claim 4, and furthercomprising clamping means on said supporting means for clamping a saidstiffening element and plate against said table.
 7. The apparatus ofclaim 4, and fastening means on said table for fastening a platethereto.
 8. The apparatus of claim 7, said fastening means comprising aplurality of magnetic means.
 9. The apparatus of claim 4, said tablehaving conveyor means associated therewith.